We present a new scale decomposition method to investigate turbulence in wavenumber-frequency space. Using 3D magnetohydrodynamic turbulence simulations, we show that magnetic fluctuations with time scales longer than the nonlinear time exhibit an inverse cascade toward even smaller frequencies. Low frequency magnetic fluctuations support turbulence, acting as an energy reservoir that is converted into plasma kinetic energy, the latter cascading toward large wavenumbers and frequencies, where it is dissipated. Our results shed new light on the spatiotemporal properties of turbulence, potentially explaining the origin and role of low frequency turbulent fluctuations in the solar wind.
@article{osti_2570044,
author = {Arrò, Giuseppe and Li, Hui and Matthaeus, William H.},
title = {Spatiotemporal Energy Cascade in Three-Dimensional Magnetohydrodynamic Turbulence},
annote = {We present a new scale decomposition method to investigate turbulence in wavenumber-frequency space. Using 3D magnetohydrodynamic turbulence simulations, we show that magnetic fluctuations with time scales longer than the nonlinear time exhibit an inverse cascade toward even smaller frequencies. Low frequency magnetic fluctuations support turbulence, acting as an energy reservoir that is converted into plasma kinetic energy, the latter cascading toward large wavenumbers and frequencies, where it is dissipated. Our results shed new light on the spatiotemporal properties of turbulence, potentially explaining the origin and role of low frequency turbulent fluctuations in the solar wind.},
doi = {10.1103/hx6s-8ns8},
url = {https://www.osti.gov/biblio/2570044},
journal = {Physical Review Letters},
issn = {ISSN 0031-9007},
number = {23},
volume = {134},
place = {United States},
publisher = {American Physical Society (APS)},
year = {2025},
month = {06}}
Cranmer, Steven R.; Asgari-Targhi, Mahboubeh; Miralles, Mari Paz
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 373, Issue 2041https://doi.org/10.1098/rsta.2014.0148